Leather-stretching machine.



PATENTED 00T. .20, 1903.

` P. F. WILLIAMS. .LEATHERSTRBTGHING MACHINE.

v APPLICATION FILED MAR. 27, 1903.

N0 MODEL.

Q n HHHIIEIII UNITED STATES Patented october 20,1903.

PATENT OFFICE.'U

FRANK F. 1WILLIAMS, OF ST. LOUIS, MISSOURI, ASSIGNOR OF ONE'HALF TO MISSOURIBELTING COMPANY, OF ST. LOUIS, MISSOURI.

LEATHER-STRETCHING MACHINE.

QSPEUIFICATION forming part of Letters Patent No. 742,114.0, dated October 20, 1903.

Application filed March 27,1903. Serial No. 149,834. (No model.)

To all whom it may concern.'

Be it known that I, FRANK F. WILLIAMS, a citizen of the United States, residing at St. Louis, in the State of Missouri, have invented certain new and useful Improvements in Leather-Stretching Machines, of which the following is a specification.

My invention relates to machines for stretching skins, hides, or other pieces of leather, especially such as are used for making belting, in which one end of the leather is held by a stationary clamping device and the opposite end is secured to aclamp mounted to move away from the stationary clamp, and thus put the leather under tension. Such clamps are usually connected together by a .board or plate in such manner that While so yconnected and While attached to the leather under tension they may be removed from the stretching-machine and set aside for a sufficiently long time to allow the leather to become permanently set.7` .The pieces of leather stretched in such machines usually have one or more irregular edges. Some stretchingmachines' have the clamps so formed that it is necessary to arrange one or more of them a considerable distance inside the irregular edge or edges at the end or ends of the leather in order to take a uniform and firm -hold thereon, and as the clamps generally mar the leather by indenting it and as a large part of the leather is not stretched by clamps so constructed a considerable portion thereof is unt for use and is Wasted.

It has been proposed to provide devices for engaging a piece of leather close to its irregular edge, and such devices have been made to conform to irregularities in the shape of the leather, but they have been complicated, requiring much time to attach them to and detach them from the leather, and thus what is saved in material is often lost in time.

The object of my invention is to provide a simple, inexpensive, and efficient means for connecting/one or more of the clamps with a piece of leather in such manner that the leather may be firmly grasped close to its edge or edges no matter what may be its irregular shape.

' It is also my object to employ a device for this purpose which may be quickly applied proved form; but one or both of the clamps instead of having the usual devices for engaging theleather are provided with devices which conform with or may be readily made to conform with the shape of the end or ends of the leather to which the clamps are applied. For this purpose I preferably use a short length of chain in each clamp, which in addition to being sufficiently strong to sustain the clamping force is adapted t0 take a firm hold'on the leather and being flexible may readily be bent into any form to adapt itself to the shape of thel leather no matter how great this irregularity may be.

It is desirable that the holding device for the leather which is interposed between the clamp members should not only have a shape corresponding with the irregular shape at the end of the leather to be stretched, but it is preferable that the holding device should be iiexible, in order that the same device may be bent into Various shapes to conformto the irregularities in different pieces of leather.

In the accompanying drawings, Figure l shows a perspective view of so 'much of a leather-stretching machine embodying my improvements as is necessary to show the mannerpof carrying out my invention. Fig. 2 shows a longitudinal section onan enlarged scale, illustrating particularly the manner in which one end of a piece of leather is clamped and held in its stretched condition. Fig. 3 shows a transversesection through the movable clamp. Fig. 4 is a perspective view illustrating the manner in which my improved leather-holding device isapplied to a piece of leather between the clamps. Fig. 5 shows a modification in Whi ch separate blocks are used instead of a chain. A

My invention does not contemplate any 'materialchangein the mechanism for stretching the leather aside from the clamping de- Vices.4

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I have shown a main frame A, on which is mounted a cross-beam B, adapted to slide back and forth longitudinally on the frame. This cross-beam is engaged by a screw-rod C, having a bearing on the main frame at D and carrying a gear-wheel E, meshing with a pinion F, connected by a short shaft with a beltpulley G.

The cross-beam B is connected by rods H with the front clamp I. The rear clamp J is connected with the rear end of the frame by hooks j, engaging staples or screw-eyes j. Any other suitable devices may be employed which will permit the rear clamp to be readily attached to or detached from the main frame. In like manner it will be observed that the rods H, connecting the cross-beam B with the front clamp, have hooks engaging loops on eyes h on the front clamp. Any other suitable connecting means may be employed which will permit the front clamp to be readily attached to and detached from the beam B.

The rear clamp J, while suspended in the main frame in such manner that it may be readily attached thereto or detached therefrom, is stationary during the stretching operation. It preferably consists of upper and lower members jS, connected by means of metal loops K and wedges 7o. The front clamp I is similarly formed, having upper and lower members t t, connected by loops I and wedges t2. The two clamps I and J are connected by means of a board or plate L, the rear end of which is permanently secured to the rear clamp and the front portion of which is loosely connected with the front clamp, so that the latter may slide longitudinally thereon.

The board L is provided with a rack-bar L', engaged by a paw] l, carried by the front clamp, the arrangement being such that as the beam B is moved forward the pawl will ride over the rack, but will engage it in such manner that the clamp I cannot recede, but will be held in the position to which it is advanced, thus holding the leather O taut.

It will be observed that the clamp members jz and ja or t' z" have flat inner surfaces which are quite extended, but which are not adapted to grasp the leather in such manner that a firm hold will be taken thereon suticient to withstand the stretching operation without slipping. Heretofore the clamp members have been formed with interlocking portions arranged straight across them and adapted to engage the leather; but such interlocking portions were not capable of being made to conform to the irregular edges on a piece of leather, and hence much ofthe leather went to waste. In order to hold the leather in the clamps, I employ a holding device which is shaped to conform approximately to the edge of the leather to be stretched, and as it is desirable that the same holding device should be employed for pieces of leather of diiferent shapes I prefer to make this holding device flexible, and therefore employ as best adapted for this purpose a short length of chain M, which while sufficiently strong to sustain the pressure whenn the clamps are connected is sufficiently flexible to be bent into any shape desired to conform to the shape of any piece of leather which it is desired to stretch.

It one end of the leather has a straight edge, it is, of course, not necessary to use a holding device of an irregular shape, and any holding device mayin such a case be usedin connection with the rear clamp. If both ends of the leather have irregular shapes, a holdingdevice such as that described is preferably employed in both clamps.

It is obvious that a somewhat similar result may be obtained by using different forms of chain or different devices, which are adapted to conform to the irregular shape of the leather to hold it at a sufficient number of points and to sustain the necessary pressure; but I know of nothing better adapted for the purpose than a short length of chain, which is preferably of the form shown and is similar to an ordinary bicycle-chain.

Somewhat the same result may beobtained by using small separate blocks of metal m, as indicated in Fig. 5, and Iconsider this modiiication as within the scope of myinvention; but in illustrating this moditication I do not wish to exclude others which might be made.

I claim as my inventionl. In a leather stretching machine, the combination of a clamp adapted to be secured to one end of a piece of leather; another clamp adapted to be secured to the opposite end thereof and comprising two members, means for connecting them and applying pressure thereto, and a holding device removably interposed between the said clamp members and shaped or arranged to conform to the irregular edge at the end of the leather to which it is applied, and means for moving one Vclamp away from the other while the leather is clamped between them.

2. The combination of two clamp members, means for connecting them and applying pressure thereto, and a flexible or adjustable holding device interposed between the clamp members and conforming in shape to the irregular edge at the end of a piece of leather to be stretched.

3. The combination of two clamp members, means for connecting them and applying pressure thereto, and a holding device interposed between the clamp members, consisting of a length of chain adapted to be bent to conform to the irregular shape at the end of the piece of leather to be stretched.

In testimony whereof I have hereunto subscribed my name.

FRANK F. WILLIAMS.

Witnesses:

W. A. HUGHES, LUCRETIA E. RICHARDSON.

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